Ion implantation apparatus and ion implantation method

Abstract

This ion implantation apparatus is provided with a holding devise which holds the wafer, and which turns it along its circumference. In addition to holding the wafer at a prescribed position, the ion implantation apparatus subjects the wafer to ion implantation in regions where there is partial overlap of its circumference. The holding devise turns and inclines the wafer, and also holds the wafer by three or more holding pins. The side face of the holding pin has an inversely tapered shape, and the multiple holding pins include a first holding pin whose protrusion amount is relatively small, and a second holding pin whose protrusion amount is relatively large. The holding pin which is on the upper side from the center of the wafer in the planar direction of the inclined wafer is the second holding pin, and the angle of inclination of the side face of the second holding pin at a position where ions are implanted into the wafer has an angular degree which is equal to or less than an angle of incidence of the ion beam relative to the wafer.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to an ion implantation apparatus which implants ions into substrates such as silicon wafers, and in particular to an ion implantation apparatus and ion implantation method which combine prevention of wafer droppage in replacement operations and inhibition of pin mark occurrence.[0003]Priority is claimed on Japanese Patent Application No. 2008-173621, filed Jul. 2, 2008, the content of which is incorporated herein by reference.[0004]2. Description of Related Art[0005]From the standpoint of fabrication of semiconductor devices which have high speed and low power consumption, SOI (Silicon on Insulator) substrates are the focus of attention. SOI substrates have embedded oxide film with excellent insulation properties, and a thin silicon layer (SOI layer) which covers this. In SOI substrates, this silicon layer is used as the active layer, thereby enabling achievement of semiconductor devices wi...

AI Technical Summary

Benefits of technology

[0017]When the wafer is inclined by turning movement, in the vicinity of the holding pins which are positioned upward relative to the center of the wafer, the force which retains the wafer that is attempting movement in the direction of the turning motion is due to physical contact from the protruding portion of the holding pins and the wafer. Consequently, when the holding pins of resin manufacture soften in a heating environment, retention by the protruding portion tends to loosen. According to the configuration of the present invention, holding force is enhanced by attachment of a second holding pin which has a relatively larger protrusion amount than the other holding pins among the holding pins of the portion. Consequently, in the present invention, compared to the case where all holding pins have the same protrusion amount, it is possible to reinforce the holding force of the holding pins that are positioned upward, and inhibit droppage.

[0019]Accordingly, according to the above type of configuration, it is possible to have an ion implantation apparatus which enables prevention of wafer droppage during replacement operations, which enables inhibition of pin mark occurrence in the vicinity of the second holding pin, and which enables satisfactory conduct of ion implantation.

[0025]As a result of study by the inventors, it was found that it is preferable to provide an angle of inclination of 5° or more in order to have satisfactory holding conducted by the holding pins. When the angle of incidence of the ion beam is less than 5° while an angle of inclination enabling satisfactory holding is provided, a protruding portion is produced wherein the second holding pin blocks the ion beam, and pin marks are created in the wafer after ion implantation. Moreover, it is unsuitable when the inclination of the wafer holder is larger than 20°, because it is difficult to conduct ion implantation into the interior of the wafer. According to the above type of configuration, ion implantation treatment can be satisfactorily conducted.

[0026]According to the present invention, by changing the shape of the holding pins according to their positional arrangement in the holding member, it is possible to offer an ion implantation apparatus which combines prevention of wafer droppage and inhibition of pin mark occurrence in the vicinity of the holding pins.

Problems solved by technology

Consequently, when the holding pins of resin manufacture soften in a heating environment, retention by the protruding portion tends to loosen.

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